Tropical Storm HARVEY

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Tropical Storm Harvey Discussion Number 38
NWS National Hurricane Center Miami FL AL092017
400 PM CDT Tue Aug 29 2017
Heavy rains continue to spread over southeastern Texas and southern
Louisiana, exacerbating what is already a catastrophic flood event.
Rainfall totals are around 50 inches at some isolated locations in
the Greater Houston area and southeastern Texas.
Convection blossomed a couple of hours ago, and the center jumped a
little northward into the thunderstorm activity. Since that time,
the center is back on track and is moving slower again toward the
north-northeast at about 5 kt. Recent data from an Air Force
Hurricane Hunter plane indicate that winds are about 45 kt, with a
minimum pressure of around 994 mb. The SFMR on the plane reported
some higher wind values but the plane was flying in shallow waters
and these numbers appear inflated. Flight-level winds in the same
area were much lower.
Strong shear prevails over the cyclone, so no significant change in
intensity is anticipated before the broad center of circulation
makes landfall. A gradual weakening is forecast once the system
moves inland.
Harvey has been steered north-northeastward by a light southwesterly
flow between a high in the Gulf of Mexico and a trough over the
central United States. This flow pattern should keep Harvey on the
same general track and speed with a gradual turn to the northeast in
about 3 days. By then the cyclone is forecast to degenerate
into a remnant low and then become absorbed by an extratropical low.
Most of the guidance is consistent with this solution, and the NHC
forecast is in the middle of the guidance envelope and very close to
the multi-model consensus.
Key Messages:
1. Ongoing catastrophic and life-threatening flooding will continue
across southeastern Texas. Additional rainfall accumulations of 6
to 12 inches are expected across the upper Texas coast into
southwestern Louisiana, with isolated storm totals as high as 50
inches. Please heed the advice of local officials. Do not attempt
to travel if you are in a safe place, and do not drive into flooded
roadways. Refer to products from your local National Weather
Service office and the NOAA Weather Prediction Center for more
information on the flooding hazard. A summary of rainfall totals
compiled by the Weather Prediction Center can be found at:
www.wpc.ncep.noaa.gov/discussions/nfdscc1.html
2. The flood threat has spread farther east, and additional rainfall
amounts of 5 to 10 inches are expected in southern Louisiana into
coastal Mississippi and Alabama. Please heed the advice of local
officials and refer to products from your local National Weather
Service office and the NOAA Weather Prediction Center for more
information on the flooding hazard in these areas.
FORECAST POSITIONS AND MAX WINDS
INIT 29/2100Z 29.2N 94.3W 45 KT 50 MPH
12H 30/0600Z 30.1N 93.7W 40 KT 45 MPH...INLAND
24H 30/1800Z 31.5N 93.0W 30 KT 35 MPH...INLAND
36H 31/0600Z 32.5N 92.5W 30 KT 35 MPH...INLAND
48H 31/1800Z 34.0N 91.0W 30 KT 35 MPH...INLAND
72H 01/1800Z 36.5N 88.0W 25 KT 30 MPH...POST-TROP/INLAND
96H 02/1800Z 37.5N 85.5W 25 KT 30 MPH...POST-TROP/INLAND
120H 03/1800Z...ABSORBED BY AN EXTRATROPICAL LOW
$$
Forecaster Avila
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